Acrylonitrile copolymers as protective overcoats in photographic elements

Abstract

Novel polymers having the structure -A)x, -B)y and -C)z; wherein A represents a polymerized acrylonitrile monomer; B represents a polymerized hydrophobic ethylenically unsaturated monomer; C represents a polymerized ionically charged vinyl monomer; x is from 10 to 90 weight percent; y is from 5 to 40 weight percent except that when B is a vinyl halide monomer, y is 10 to 89.9 weight percent; and z is from 0.1 to 10 weight percent The polymers are useful in forming protective overcoats for photographic elements.

We claim: 
     
       1. A photographic element comprising a support, at least one radiation sensitive layer and an overcoat layer comprising a aqueous latex polymer characterized in that the polymer comprises random recurring units having the structure:   --A).sub.x, --B).sub.y and --C).sub.z ;     wherein   A represents a polymerized acrylonitrile monomer;   B represents a polymerized hydrophobic ethylenically unsaturated monomer;   C represents a polymerized ionically charged vinyl monomer; x is from 10 to 90 weight percent;   y is from 5 to 40 weight percent except when B is a vinyl halide monomer, y is 10 to 89.9 weight percent; and   z is from 0.1 to 10 weight percent.     
     
     
       2. A photographic element comprising a support having on one side thereof a radiation-sensitive layer and on the other side thereof, an antistatic layer overcoated with a layer comprising a aqueous latex polymer having random recurring units of the structure:   --A).sub.x, --B).sub.y and --C).sub.z ;     wherein   A represents a polymerized acrylonitrile monomer;   B represents a polymerized hydrophobic ethylenically unsaturated monomer;   C represents a polymerized ionically charged vinyl monomer; x is from 10 to 90 weight percent;   y is from 5 to 40 weight percent except when B is a vinyl halide monomer, y is 10 to 89.9. weight percent; and   z is from 0.1 to 10 weight percent.     
     
     
       3. The elements of claim 1 or 2 wherein B is selected from the group consisting of polymerized alkyl acrylates, alkyl methacrylates and vinylidene chloride;   C is selected from the group consisting of polymerized N-(2-methacryloyloxyethyl)-N,N,N-trimethylammonium methosulfate; N,N,N-trimethyl-N-vinylbenzylammonium chloride and N-(3-methacrylamidopropyl)-N,N,N-trimethylammonium chloride and sodium 2-acrylamido-2-methylpropanesulfonate; x is from 20 to 80 weight percent;   y is from 10 to 30 weight percent except when B is vinylidene chloride, y is 15 to 79.9 weight percent; and   z is from 0.1 to 2 weight percent.     
     
     
       4. The elements of claim 1 or 2 wherein the overcoat includes an abrasion resistant agent. 
     
     
       5. The element of claim 1 or 2 wherein the polymeric overcoat comprises a polymer selected from the group consisting of poly[n-butyl acrylate-co-acrylonitrile-co-N-(2-methacryloyloxyethyl)-N,N,N-trimethylammonium methosulfate] (weight ratio 20/78/2);   poly[ethyl acrylate-co-acrylonitrile-co-N-(2-methacryloyloxyethyl)-N,N,N-trimethylammonium methosulfate] (weight ratio 23.9/76/0.1);   poly[vinylidene chloride-co-acrylonitrile-co-N-(2-methacryloyloxyethyl)-N,N,N-trimethylammonium methosulfate] (weight ratio 73/25/1.6);   poly[vinylidene chloride-co-acrylonitrile-co-N-(2-methacryloyloxyethyl)-N,N,N-trimethylammonium methosulfate] (weight ratio 58/40/1.6); and   poly(ethylacrylate-co-acrylonitrile-co-2-acryl-amido-2-methylpropanesulfonate) (weight ratio 23.9/76/0.1).   
     
     
       6. The element of claim 2 wherein the antistatic layer comprises a coalesced, cationically stabilized latex binder and a polyaniline imine salt semiconductor. 
     
     
       7. The element of claim 1 or 2 wherein the overcoats include an abrasion resistant agent.